Method for controlling viral diseases in plants

Abstract

Chemicals containing an effective amount of a polymer of a specified salt of diallylamine derivative and/or a diallyl quarternary ammonium salt exhibit a remarkable effect of preventing agricultural plants from being infected with viral diseases in plants. A method for controlling viral diseases in plants by using an effective amount of such polymer is described.

We claim: 
     
       1. A method for preventing viral diseases in plants comprising applying to said plants an antiviral effective amount of a polymer produced by the polymerization of one or two compounds expressed by the following general formula: ##STR28## wherein R 1  and R 2 , which may be the same or not, represent a hydrogen atom or an alkyl group having 1-5 carbon atoms which may be substituted by a halogen atom, a hydroxyl group or a cyano group, or together form a pyrrolidine, piperidine, or morpholine ring with the nitrogen to which they are attached, and X is a halogen atom. 
     
     
       2. A method according to claim 1, wherein R 1  and R 2  together form a piperidine ring or a morpholine ring with the nitrogen to which they are attached. 
     
     
       3. A method according to claim 1, wherein viral diseases in said plants are selected from the group consisting of tobacco mosaic virus, cucumber mosaic virus, cucumber green mottle mosaic virus, potato X virus, lettuce mosaic virus and melon necrotic spot virus. 
     
     
       4. A method according to claim 3, wherein the viruses are selected from the group consisting of tobacco mosaic virus, cucumber mosaic virus and cucumber green mottle mosaic virus. 
     
     
       5. A method according to claim 1, wherein R 1  and R 2 , which may be the same or not, represent a hydrogen atom, a linear alkyl group having 1-3 carbon atoms, a β-hydroxyethyl group, a β-cyanoethyl group or a β-hydroxy-γ-halopropyl group. 
     
     
       6. A method according to claim 1, wherein the polymer is a copolymer produced from two compounds selected from the following groups (A) and (B); ##STR29## wherein, R 1  and R 2  represent an alkyl group having 1-3 carbon atoms and X represents a halogen atom. ##STR30## wherein, R 1  represents a hydrogen atom, R 2  represents a β-hydroxyethyl group, a β-cyanoethyl group or a β-hydroxy-γ-chloropropyl group, and X represents a halogen atom. 
     
     
       7. A method according to claim 1, wherein the polymer is a homopolymer of a compound expressed by the following general formula: ##STR31## wherein R 1  and R 2  represent a hydrogen atom, a linear alkyl group having 1-3 carbon atoms, a β-hydroxyethyl group, a β-cyanoethyl group or a β-hydroxy-γ-chloropropyl group and may form a pyrrolidine or together form a piperidine or a morpholine with the nitrogen they attach to, and X represents a halogen atom. 
     
     
       8. A method according to claim 7, wherein R 1  and R 2  represent a methyl group, a ethyl group or a β-hydroxy-γ-chloropropyl group. 
     
     
       9. A method according to claims 6 or 7, wherein X represents a chlorine atom or a bromine atom. 
     
     
       10. A method according to claim 6, wherein the copolymer is produced from (3-chloro-2-hydroxy) propyl diallylamine hydrochloride and dimethyl allyl ammonium chloride. 
     
     
       11. A method according to claim 6, wherein the rotational viscosity of the copolymer is in the range of from 1.5 to 30 cps in 0.2 wt % aqueous solution at 20° C. 
     
     
       12. A method according to claim 7, wherein the rotational viscosity of the homopolymer is in the range of from 2.0 to 30 cps in 0.2 wt % aqueous solution at 20° C. 
     
     
       13. A method according to claim 1, wherein the plant is Solanaceae, Cucurbitaceae, Leguminosae, Crucifeceae or Rosaceae. 
     
     
       14. A method according to claim 1, wherein the plant is Solanaceae such as tobacco, tomato or green pepper, or Cucurbitaceae such as cucumber, watermelon or melon. 
     
     
       15. A method according to claim 14, wherein the plant is tomato or tobacco. 
     
     
       16. A method according to claim 1, wherein there is used a wettable powder for controlling viral diseases in plants comprising 70-99 parts by weight of the polymer of claim 1, and 1-30 parts by weight of a surface active agent. 
     
     
       17. A method according to claim 1 comprising applying to said plants an emulsion or solution for controlling viral diseases in plants comprising 10-60 parts by weight of the polymer of claim 1, 20-90 parts by weight of a solvent, and 1-20 parts by weight of a surface active agent.